A DFB device with refrigeration and its assembling method

Abstract

This invention relates to the field of optical communication device technology, and provides a cooled DFB device and its assembly method. The device includes a TEC (Transmission Device), a TO (Top-Order) base, a laser chip, and an FPC (Flexible Printed Circuit) strip. The TEC is disposed on the TO base, and the laser chip is disposed on the TEC. The TO base has a first pin and a second pin. The FPC strip has a first circuit line and a second circuit line printed on it. One end of the first circuit line is connected to the first pin, and the other end of the first circuit line is connected to one electrode of the laser chip. One end of the second circuit line is connected to the second pin, and the other end of the first circuit line is connected to the other electrode of the laser chip, so as to connect the two electrodes of the laser chip to the first pin and the second pin through the FPC strip. This invention uses the FPC strip to effectively avoid heat exchange between the heat generated by the laser chip and the external environment, ensuring the temperature control capability of the TEC.

Description

Technical Field

[0001] This invention relates to the field of optical communication device technology, and in particular to a cooled DFB device and its assembly method. Background Technology

[0002] Existing high-speed Transmitter Optical (TO) devices, due to increasingly stringent requirements on speed and wavelength, generally employ temperature control with a thermoelectric cooler (TEC). Considering the limited size and cooling / heating capacity of the TEC, TO designs typically aim to isolate the temperature-controlled surface where the laser chip is housed from the external environment as much as possible to reduce heat transfer between the TEC and the external environment. For example... Figure 1 As shown, due to the requirements of electrical signals and anti-oxidation, gold wire is usually used to connect the laser chip to the corresponding pin on the TO base. Gold wire is a good conductor of heat and has excellent thermal conductivity. Through the guidance of the gold wire and the corresponding pin on the TO base, the heat inside the TO can easily exchange with the external environment, which greatly reduces the temperature control effect of the TEC. If the length of the gold wire is increased to reduce the thermal load of the TEC by lengthening the temperature gradient, the parasitic parameters of the gold wire (mainly referring to the parasitic resistance of the gold wire) will increase linearly, which will lead to greater loss of high-speed electrical signals. If the temperature control capability of the TEC is increased, the number of semiconductor pillars needs to be increased, the volume of the TEC will increase, and the space available in the small space of the TO is limited, which also does not meet the current demand for miniaturization of TO.

[0003] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0004] The problem to be solved by the embodiments of the present invention is how to solve the problem that the existing TO uses gold wire to connect the internal laser chip to the corresponding pin on the TO base, which makes the inside of the TO more likely to exchange heat with the external environment, thus reducing the temperature control capability of TEC1.

[0005] The embodiments of the present invention adopt the following technical solutions:

[0006] In a first aspect, the present invention proposes a DFB device with cooling, comprising a TEC1, a TO base 2, a laser chip 3, and an FPC flexible strip 4 (Flexible Printed Circuit).

[0007] The TEC1 is mounted on the TO base 2, and the laser chip 3 is mounted on the TEC1;

[0008] The TO base 2 is provided with a first pin 21 and a second pin 22, and the FPC flexible strip 4 is printed with a first circuit line 41 and a second circuit line 42.

[0009] One end of the first circuit line 41 is connected to the first pin 21, and the other end of the first circuit line 41 is connected to one pole of the laser chip 3. One end of the second circuit line 42 is connected to the second pin 22, and the other end of the first circuit line 41 is connected to the other pole of the laser chip 3, so as to connect the two poles of the laser chip 3 with the first pin 21 and the second pin 22 through the FPC flexible strip 4.

[0010] Preferably, matching resistors are provided on the first circuit 41 and / or the second circuit 42 to improve signal integrity.

[0011] Preferably, the DFB device with cooling further includes a backlight detection chip 5, a first light output port 31 is provided on the laser chip 3, a ceramic substrate 6 is provided on the TEC1, the laser chip 3 is disposed on the ceramic substrate 6, and a third pin 23 is provided on the TO base 2.

[0012] The backlight detection chip 5 is electrically connected to the third pin 23. The backlight detection chip 5 is disposed on the ceramic substrate 6 and is coupled and aligned with the first light outlet 31.

[0013] Preferably, a thermistor 7 is disposed on the ceramic substrate 6, and a fourth pin 24 is disposed on the TO base 2; the thermistor 7 is electrically connected to the fourth pin 24.

[0014] Preferably, the cooled DFB device further includes a reflector 8, and the laser chip 3 is provided with a second light output port 32;

[0015] The reflector 8 is disposed on the ceramic substrate 6, and the reflector 8 is coupled and aligned with the second light output port 32 of the laser chip 3;

[0016] The reflector 8 has a light-incident surface 81, which is set at a first preset angle with the second light-out port 32. The light-incident surface 81 is used to refract light signals.

[0017] Preferably, the DFB unit with cooling further includes a TO cap 9, an adapter 10, and a tube body 11;

[0018] The TO cap 9 is disposed on the TO base 2, and the adapter 10 contains an optical fiber;

[0019] One end of the tube 11 is fitted onto the TO cap 9, and the other end of the tube 11 is connected to the adapter 10.

[0020] Secondly, the present invention also proposes an assembly method for a cooled DFB device, applicable to the cooled DFB device of the first aspect, the assembly method comprising:

[0021] The TEC1 is mounted on the TO base 2, and the laser chip 3 is placed on the TEC1;

[0022] Connect one end of the first circuit line 41 printed on the FPC flexible tape 4 to the first pin 21 on the TO base 2, and connect the other end of the first circuit line 41 printed on the FPC flexible tape 4 to one pole of the laser chip 3.

[0023] One end of the second circuit line 42 printed on the FPC flexible tape 4 is connected to the second pin 22 on the TO base 2, and the other end of the second circuit line 42 printed on the FPC flexible tape 4 is connected to the other pole of the laser chip 3, so as to realize the connection between TEC1, TO base 2, laser chip 3 and FPC flexible tape 4.

[0024] Preferably, the assembly also includes the assembly of the adapter 10, adjusting ring 12, tube body 11, TO cap 9, backlight detection chip 5, ceramic substrate 6, reflector 8 and thermistor 7, wherein the assembly method specifically includes:

[0025] The ceramic substrate 6 is mounted on the TEC1, and the laser chip 3, the backlight detection chip 5, the reflector 8 and the thermistor 7 are mounted on the preset positions of the ceramic substrate 6, and the TEC1 is mounted on the TO base 2.

[0026] The laser chip 3 is connected to the TO base 2 via FPC flexible tape 4, the backlight detection chip 5 is connected to the third pin 23 via gold wire, and the thermistor 7 is connected to the fourth pin 24.

[0027] Install the TO cap 9 on the TO base 2, and attach one end of the tube body 11 to the TO cap 9;

[0028] Install the adjustment ring 12 on the other end of the tube 11, and install the adapter 10 on the adjustment ring 12. Rotate the adapter 10 so that the optical fiber inside the adapter 10 is coupled and aligned with the optical signal generated by the laser chip 3.

[0029] Preferably, before connecting the laser chip 3, the third pin 23, and the fourth pin 24 using the FPC flexible strip 4, a matching resistor 43 is further provided within the FPC flexible strip 4, specifically including:

[0030] Monitor the oscillation circuits at both ends of the laser chip 3, and adjust the matching resistor 43 on the FPC soft strip 4 from 0Ω in preset gradient steps each time, and measure the integrity of the output signal of the FPC soft strip 4 under each matching resistor 43.

[0031] Once the integrity of the monitored signal reaches the preset effect, the final target matching resistor 43 value on the FPC softband 4 is obtained.

[0032] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows:

[0033] The DFB device with cooling in this invention is equipped with a TEC1, which is mounted on the TO base 2. The laser chip 3 is mounted on the TEC1. The TEC1 mainly functions to regulate the operating temperature of the laser chip 3, so that the laser chip 3 is maintained within the normal operating range through the regulation of the TEC1. In this invention, the laser chip 3 is connected to the first pin 21 and the second pin 22 on the TO base 2 using an FPC flexible strip 4. The first pin 21 and the second pin 22 are input signal pins. The FPC flexible strip 4 is a poor conductor of heat with very poor thermal conductivity (compared to the gold wire of the prior art), which can effectively prevent the heat generated by the laser chip 3 from exchanging with the external environment, thus not affecting the temperature control capability of the TEC1. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure where the laser chip provided by the existing technology is connected to the corresponding pin on the TO base using gold wire;

[0036] Figure 2 This is a schematic diagram of the structure of a DFB device with cooling provided in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of an FPC flexible strip structure for a DFB device with cooling provided in an embodiment of the present invention;

[0038] Figure 4 This is an equivalent circuit diagram of an FPC flexible tape with a cooling DFB device provided in an embodiment of the present invention;

[0039] Figure 5This is a schematic diagram of the structure of a DFB device with cooling provided in an embodiment of the present invention from another perspective;

[0040] Figure 6 This is a schematic diagram of the structure of a laser chip with a cooling DFB device provided in an embodiment of the present invention;

[0041] Figure 7a This is a cross-sectional view of the overall structure of a DFB device with cooling provided in an embodiment of the present invention;

[0042] Figure 7b This is a schematic diagram of the overall structure of a DFB device with cooling provided in an embodiment of the present invention;

[0043] Figure 8 This is an optical path diagram of a laser chip in a cooled DFB device reflecting light through a mirror, provided by an embodiment of the present invention.

[0044] Figure 9 This is a flowchart of an assembly method for a DFB device with cooling provided in an embodiment of the present invention;

[0045] Figure 10 This is a flowchart illustrating an assembly method for a DFB device with cooling, comprising an internal adapter, adjustment ring, tube body, TO cap, backlight detection core, ceramic substrate 6, reflector, and thermistor, according to an embodiment of the present invention.

[0046] Figure 11 This is a flowchart of a method for setting a matching resistor in the FPC flexible strip of a DFB device with cooling, according to an embodiment of the present invention.

[0047] 1-TEC; 2-TO base; 21-Pin 1; 22-Pin 2; 23-Pin 3; 24-Pin 4; 3-Laser chip; 31-First light output port; 32-Second light output port; 4-FPC flexible tape; 41-First circuit line; 42-Second circuit line; 43-Matching resistor; 5-Backlight detection chip; 6-Ceramic substrate; 7-Thermistor; 8-Reflector; 81-Light incident surface; 9-TO cap; 10-Adapter; 11-Tube body; 12-Adjustment ring. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0049] In the description of this invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and do not require that this invention must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0050] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0051] In this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "coupled" can refer to an electrical connection that enables signal transmission.

[0052] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Example 1:

[0054] Embodiment 1 of the present invention provides a cooled DFB (Distributed Feedback Laser) device, such as... Figures 2-3 As shown, it includes TEC1, TO base 2, laser chip 3 and FPC flexible strip 4.

[0055] The TEC1 is mounted on the TO base 2, and the laser chip 3 is mounted on the TEC1.

[0056] The TO base 2 is provided with a first pin 21 and a second pin 22, and the FPC flexible tape 4 is printed with a first circuit line 41 and a second circuit line 42; wherein... Figure 3 To facilitate understanding of the first circuit line 41 and the second circuit line 42 printed inside the FPC flexible tape 4, Figure 3 The first circuit line 41 and the second circuit line 42 of the FPC flexible tape 4 are represented by dashed lines.

[0057] One end of the first circuit line 41 is connected to the first pin 21, and the other end of the first circuit line 41 is connected to one pole of the laser chip 3. One end of the second circuit line 42 is connected to the second pin 22, and the other end of the first circuit line 41 is connected to the other pole of the laser chip 3, so as to connect the two poles of the laser chip 3 with the first pin 21 and the second pin 22 through the FPC flexible strip 4.

[0058] In this embodiment of the invention, a cooling DFB device is provided with a TEC1, and the laser chip 3 is disposed on the TEC1. The TEC1 is mainly used for temperature control of the laser chip 3. By cooling or heating the laser chip 3, the temperature of the laser chip 3 is compensated, so that the laser chip 3 can be maintained within a normal operating temperature range. In this embodiment of the invention, an FPC flexible strip 4 is used to replace the existing gold wire to connect the two poles of the laser chip 3 to the first pin 21 and the second pin 22 provided on the TO base 2. Gold wire is a good conductor of heat, while FPC flexible strip 4 is a poor conductor of heat. Compared with gold wire, the use of FPC flexible strip 4 in this embodiment of the invention can effectively avoid heat exchange between the heat generated by the laser chip 3 and the external environment, thus not affecting the temperature control capability of the TEC1. It is worth noting that regarding the temperature control capability of TEC1, when the operating temperature of the laser chip 3 is lower or higher than the normal operating temperature range, TEC1 starts to work to compensate for the temperature of the laser chip 3. During the compensation process, part of the temperature control capability of TEC1 is applied to the laser chip 3, and another part is applied to the external environment. When the proportion of the temperature control capability of TEC1 applied to the external environment is larger, the temperature control capability of TEC1 will decrease. For example, assuming that when the laser chip 3 exceeds the normal temperature range, through calculation, theoretically, TEC1 needs to dissipate heat A to the laser chip 3. After adjusting TEC1, it is found that even after dissipating heat A to the laser chip 3, the temperature of the laser chip 3 is still higher than the normal temperature range. This indicates that there is a certain factor (heat exchange with the external environment) affecting the temperature control capability of TEC1. For the existing technology, the main factor affecting the temperature control capability of TEC1 is that the laser chip 3 and the TO base 2 are connected by gold wire, which causes the laser chip 3 to exchange heat with the external environment through the gold wire.

[0059] To further illustrate the complete solution of the embodiments of the present invention, the details of the embodiments of the present invention will be described in detail below. Since DFB devices contain parasitic inductance, parasitic capacitance, and parasitic resistance, oscillating current will be generated within the circuit during high-frequency signal transmission, causing the transmitted signal to oscillate, thereby leading to distortion in the signal output process and affecting signal integrity; theoretically, the larger the oscillating current, the more severe the distortion, i.e., the larger the current, the more severe the distortion. Based on this, as... Figure 4As shown, in this embodiment of the invention, matching resistors are provided on the first circuit 41 and / or the second circuit 42 to improve signal integrity.

[0060] In this embodiment of the invention, a matching resistor 43 is provided on the FPC flexible strip 4. Specifically, but not limited to, the matching resistor 43 can be provided on the first circuit line 41 and / or the second circuit line 42 (i.e., matching resistors 42 are provided on the first circuit 41 and the second circuit 42 respectively, see reference). Figure 4 As shown, a matching resistor 43 can also be provided only on the first circuit line 41 or the second circuit line 42. The other end of the first circuit line 41 is connected to one pole of the laser chip 3, and the other end of the second circuit line 42 is connected to the other pole of the laser chip 3. The matching resistor 43 is provided on the first circuit line 41 and / or the second circuit line 42, and the matching resistor 43 is connected in series with the laser chip 3, which reduces the current flowing into the laser chip 3, thereby reducing the degree of distortion of the laser chip 3. In order to ensure the integrity of the signal as much as possible, the size of the matching resistor 43 in this embodiment of the invention is determined by the equivalent resistance and output impedance of the laser chip 3. It should not be too large or too small. When the matching resistor 43 is too large, the current of the laser chip 3 is too small, resulting in a weak monitored signal. When the matching resistor 43 is too small, the oscillation current on the laser chip 3 is large, resulting in severe signal distortion and reduced signal integrity. In actual use, this embodiment of the invention determines the size of the matching resistor 43 by setting a threshold for signal integrity (or setting a threshold for the proportion of distorted signal). In addition, different laser chips 3 have different values ​​of parasitic capacitance, parasitic inductance, and parasitic resistance, therefore the value of the matching resistor 43 will also be different. In the actual process of determining the matching resistor 43, in cases such as... Figure 4 In the circuit shown, the matching resistor 43 is set in steps from 0 ohms with a preset resistance gradient. The value is monitored by an external oscilloscope to finally obtain the matching resistor 43 that satisfies the signal integrity. After the value of the matching resistor 43 on the FPC soft strip 4 is determined, the corresponding matching resistor 43 can be added to the first circuit line 41 and / or the second circuit line 42 in a thin film manner to optimize the signal integrity.

[0061] like Figures 5-6 As shown, the DFB device with cooling described in this embodiment of the invention also includes a backlight detection chip 5, a first light output port 31 is provided on the laser chip 3, a ceramic substrate 6 is provided on the TEC1, the laser chip 3 is disposed on the ceramic substrate 6, and a third pin 23 is provided on the TO base 2.

[0062] The backlight detection chip 5 is electrically connected to the third pin 23. The backlight detection chip 5 is disposed on the ceramic substrate 6 and is coupled and aligned with the first light outlet 31.

[0063] In this embodiment of the invention, a ceramic substrate 6 is disposed between the laser chip 3 and the TEC1. In the actual setup process, the ceramic substrate 6 is first placed on the TEC1, and then the laser chip 3 and the backlight detector are placed on the ceramic substrate 6. The laser chip 3 is provided with a first light output port 31, and the first light output port 31 is coupled and aligned with the backlight detector chip 5. A portion of the optical signal generated by the laser chip 3 is transmitted to the backlight detector chip 5 through the first light output port 31. The backlight detector chip 5 is connected to the third pin 23, and the backlight detector chip 5 converts the optical signal into a monitoring current output from the third pin 23 on the TO base 2.

[0064] To ensure that laser chip 3 is always maintained within the normal operating temperature range, such as Figure 5 As shown, in this embodiment of the invention, a thermistor 7 is disposed on the ceramic substrate 6, and a fourth pin 24 is disposed on the TO base 2; the thermistor 7 is electrically connected to the fourth pin 24.

[0065] In this embodiment of the invention, a thermistor 7 is disposed on a ceramic substrate 6, and a laser chip 3 is disposed on the ceramic substrate 6. Heat exchange occurs between the laser chip 3 and the ceramic substrate 6. The temperature of the ceramic substrate 6 is measured by the thermistor 7, which indirectly reflects the operating temperature of the laser chip 3. Then, by adjusting the TEC1 for cooling or heating, the temperature of the laser chip 3 is adjusted to its normal operating range. It is worth noting that the resistance of the thermistor 7 changes with temperature. In this embodiment, a fourth pin 24 is provided on the TO base 2, and the thermistor 7 is electrically connected to the fourth pin 24. Temperature changes on the ceramic substrate 6 cause changes in the value of the thermistor 7, which in turn causes changes in the branch current at the thermistor 7. The current in the branch where the thermistor 7 is located is output through the fourth pin 24, thereby measuring the temperature of the ceramic substrate 6.

[0066] In order to input the optical signal generated by the laser chip 3 into the optical fiber in the adapter 10 (see...) Figures 7a-7b As shown, the fiber optic cable being installed inside the adapter is existing technology. Figures 7a-7b (Not shown in the text) In the text, such as Figures 5-8 As shown, where, Figure 8The dashed line in the figure represents the optical path of the signal light emitted by the laser chip 3, which is reflected and redirected by the light-incident surface 81 of the reflector 8 before entering the optical fiber inside the adapter. The DFB device with cooling according to this embodiment of the invention also includes the reflector 8, and the laser chip 3 is provided with a second light-out port 32. The reflector 8 is disposed on the ceramic substrate 6, and the reflector 8 is coupled and aligned with the second light-out port 32 of the laser chip 3. The reflector 8 has a light-incident surface 81, which is set at a first preset angle with the second light-out port 32, and the light-incident surface 81 is used to refract the optical signal. In addition, the DFB device with cooling according to this embodiment of the invention also includes a TO cap 9, an adapter 10, and a tube body 11. The TO cap 9 is disposed on the TO base 2, and the adapter 10 contains an optical fiber. One end of the tube body 11 is sleeved on the TO cap 9, and the other end of the tube body 11 is connected to the adapter 10.

[0067] In this embodiment of the invention, the laser chip 3 of the cooled DFB device is provided with a second light output port 32. Another portion of the optical signal generated by the laser chip 3 is transmitted from the second light output port 32 to the light incident surface 81 of the reflector 8. In this embodiment of the invention, the first preset angle between the light incident surface 81 of the reflector 8 and the optical signal generated by the laser chip at the second light output port 32 is preferably set to 45°. Through the reflection effect of the 45° light incident surface 81, the optical signal transmitted from the second light output port 32 is transmitted along the direction perpendicular to the TO base 2 into the optical fiber of the adapter 10. It is worth noting that the ratio of light emitted from the first light-emitting port 31 and the second light-emitting port 32 of the laser chip 3 in this embodiment of the invention is set according to the actual situation. The first light-emitting port 31 is coupled to the backlight detection chip 5 and is mainly used to monitor the signal of the laser chip 3. The second light-emitting port 32 is coupled to the reflector 8 and is mainly used to transmit the light signal generated by the laser chip 3 to the corresponding optical fiber. Therefore, the proportion of light emitted from the second light-emitting port 32 in this embodiment of the invention is much greater than the proportion of light emitted from the first light-emitting port 31. For example, in this embodiment of the invention, the proportion of light emitted from the first light-emitting port 31 can be set to 10% and the proportion of light emitted from the second light-emitting port 32 can be set to 90%.

[0068] To avoid signal light reflection, the end face of the optical fiber is typically tilted at approximately 5°. To ensure the optical signal generated by the laser chip 3 from the second output port 32 is smoothly reflected by the reflector 8 and enters the optical fiber within the adapter 10, such as... Figures 7a-7b As shown, in this embodiment of the invention, an adjustment ring 12 is provided between the adapter 10 and the tube body 11. The adapter 10 is rotatably mounted on the adjustment ring 12. The direction of the optical fiber tilt angle is adjusted by rotating the adapter 10, so as to couple and align the optical fiber in the adapter 10 with the optical signal generated by the laser chip 3.

[0069] This invention utilizes an FPC flexible strip 4 instead of the existing gold wire to connect the two poles of the laser chip 3 to the first pin 21 and the second pin 22 on the TO base 2. Gold wire is a good conductor of heat, while the FPC flexible strip 4 is a poor conductor. Compared to gold wire, the use of the FPC flexible strip 4 in this invention effectively avoids heat exchange between the laser chip 3 and the external environment, thus not affecting the temperature control capability of the TEC1. This invention also compensates for the oscillation circuit generated by setting a matching resistor 43 on the FPC flexible strip 4, thereby optimizing signal integrity. Furthermore, the parasitic parameters of the FPC flexible strip 4 are much smaller than those of the gold wire, allowing for an increase in the length of the FPC flexible strip 4 during actual implementation, increasing the adjustable length margin. The FPC does not impose many restrictions on the pin distribution of the TO base 2, allowing for arbitrary adjustment of pin positions, thus enabling miniaturization of multi-pin TO base 2.

[0070] Example 2:

[0071] This invention also provides an assembly method for a cooled DFB device, which is applied to the cooled DFB device in Embodiment 1, such as... Figure 9 As shown, the assembly method includes:

[0072] Step 201: Mount the TEC1 onto the TO base 2 and place the laser chip 3 on the TEC1.

[0073] In this embodiment of the invention, the laser chip 3 is mounted on the TEC1. The TEC1 heats or cools the laser chip 3 according to its actual temperature and normal operating temperature range to maintain the laser chip 3 within its normal operating temperature range. It is worth noting that in the actual assembly process, the TEC1 is first mounted on the TO base 2, then the ceramic substrate 6 is mounted on the TEC1, and finally the laser chip 3 is mounted on the ceramic substrate 6. In addition, this embodiment of the invention can, but is not limited to, use eutectic bonding to weld the laser chip 3 onto the ceramic substrate 6.

[0074] Step 202: Connect one end of the first circuit line 41 printed on the FPC flexible tape 4 to the first pin 21 on the TO base 2, and connect the other end of the first circuit line 41 printed on the FPC flexible tape 4 to one pole of the laser chip 3.

[0075] In this embodiment of the invention, the FPC soft strip 4 replaces the traditional gold wire, retaining the function of conducting circuit while also having low heat transfer performance, belonging to poor thermal conductivity.

[0076] Step 203: Connect one end of the second circuit line 42 printed on the FPC flexible tape 4 to the second pin 22 on the TO base 2, and connect the other end of the second circuit line 42 printed on the FPC flexible tape 4 to the other pole of the laser chip 3, so as to realize the connection between TEC1, TO base 2, laser chip 3 and FPC flexible tape 4.

[0077] In the FPC flexible strip 4 of this embodiment of the invention, the first circuit line 41 and the second line can be understood as two wires that connect the two poles of the laser chip 3 to the corresponding pins (including the first pin 21 and the second pin 22) so as to transmit the signal of the laser chip 3.

[0078] This invention also includes the assembly of the adapter 10, adjustment ring 12, tube body 11, TO cap 9, backlight detection chip 5, ceramic substrate 6, reflector 8, and thermistor 7, such as... Figure 10 As shown, the assembly method specifically includes:

[0079] Step 301: Mount the ceramic substrate 6 onto the TEC1, and mount the laser chip 3, backlight detection chip 5, reflector 8 and thermistor 7 onto the preset positions on the ceramic substrate 6, and mount the TEC1 onto the TO base 2.

[0080] In the actual assembly process of the DFB device with cooling in this embodiment of the invention, the laser chip 3 is not directly mounted on the TEC1. Instead, the ceramic substrate 6 is first mounted on the TEC1, and then the laser chip 3, the backlight detection chip 5, the reflector 8, and the thermistor 7 are mounted on the corresponding positions on the ceramic substrate 6. The preset positions for mounting the laser chip 3, the backlight detection chip 5, the reflector 8, and the thermistor 7 are determined according to the actual situation, and will not be elaborated here.

[0081] Step 302: Connect the laser chip 3 to the TO base 2 via the FPC flexible strip 4, connect the backlight detection chip 5 to the third pin 23 via gold wire, and connect the thermistor 7 to the fourth pin 24.

[0082] In this embodiment of the invention, the temperature change inside the cooled DFB device is mainly due to the heat generated by the laser chip 3 during operation. Therefore, in this embodiment, FPC flexible tape 4 is used to connect the two electrodes of the laser chip 3 to the first pin 21 and the second pin 22 on the TO base 2. Other devices mounted on the ceramic substrate 6 (including the backlight detection chip 5, thermistor 7, and TEC1) are directly connected to the corresponding pins of the TO base 2 using gold wires. It is worth noting that the TO base 2 in this embodiment of the invention is provided with pins for connecting the two electrodes of the TEC1 (see...). Figure 2 or Figure 5 As shown in the figure (not marked), TEC1 is turned on through the corresponding pin, and the temperature of laser chip 3 is adjusted through TEC1.

[0083] Step 303: Install the TO cap 9 on the TO base 2 and attach one end of the tube body 11 to the TO cap 9; install the adjustment ring 12 on the other end of the tube body 11 and install the adapter 10 on the adjustment ring 12. Rotate the adapter 10 so that the optical fiber inside the adapter 10 is coupled and aligned with the optical signal generated by the laser chip 3.

[0084] In this embodiment of the invention, after the adapter 10 is placed inside the corresponding adjustment ring 12, rotating the adapter 10 allows the optical fiber to couple and align with the optical signal generated by the laser chip 3. It is worth noting that in this embodiment of the invention, the reflector 8, the backlight detection chip 5, and the thermistor 7 are all mounted on the ceramic substrate 6. This embodiment of the invention can, but is not limited to, use adhesive bonding to mount the reflector 8, the backlight detection chip 5, and the thermistor 7 onto the ceramic substrate 6. Similarly, the ceramic substrate 6 can, but is not limited to, be mounted on the TEC1 using adhesive bonding.

[0085] In addition, before connecting the laser chip 3, the third pin 23, and the fourth pin 24 using the FPC flexible strip 4, this embodiment of the invention also includes setting a matching resistor 43 within the FPC flexible strip 4, such as... Figure 11 As shown, it specifically includes:

[0086] Step 401: Monitor the oscillation circuits at both ends of the laser chip 3, and adjust the matching resistor 43 on the FPC flexible strip 4 from 0Ω in preset gradient steps each time, and measure the integrity of the output signal of the FPC flexible strip 4 under each matching resistor 43.

[0087] In this embodiment of the invention, signal integrity actually represents signal quality, not signal strength. After setting the corresponding matching resistor 43 value, the integrity of the output signal of the FPC flexible band 4 is measured using an oscilloscope. In this embodiment, the matching resistor 43 on the FPC flexible band 4 starts from 0Ω and increases in steps (e.g., 0Ω, 2Ω, 4Ω, 6Ω, 8Ω), with the corresponding value measured using an oscilloscope after each increase. The gradient of the step is set according to actual conditions and will not be elaborated here.

[0088] Step 402: After the integrity of the monitored signal reaches the preset effect, obtain the final target matching resistor 43 value on the FPC soft band 4.

[0089] In practical applications, it is necessary to ensure both measurable data and signal integrity. Therefore, the current in this embodiment of the invention cannot be too small or too large, and the corresponding matching resistor 43 on the FPC flexible band 4 cannot be too small or too large. Thus, in practical applications, this embodiment of the invention typically sets a signal integrity threshold (or the proportion of signal distortion). Step 401 measures the corresponding signal integrity or the proportion of signal distortion. When the signal integrity is found to meet a preset standard, the matching resistor 43 of the FPC flexible band 4 is determined. It is worth noting that, based on the signal integrity threshold setting, the matching resistor 43 of the FPC flexible band 4 in this embodiment of the invention is actually a resistance range. Matching resistors 43 falling within this resistance range meet the signal integrity threshold requirements.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A DFB device with refrigeration, characterized in that, Includes TEC (1), TO base (2), laser chip (3) and FPC flexible tape (4); The TEC (1) is disposed on the TO base (2), and the laser chip (3) is disposed on the TEC (1); specifically, a ceramic substrate (6) is disposed on the TEC (1), and the laser chip (3) is disposed on the ceramic substrate (6); the larger side of the ceramic substrate (6) is placed flat on the TEC (1); The TO base (2) is provided with a first pin (21) and a second pin (22), and the FPC soft strip (4) is printed with a first circuit line (41) and a second circuit line (42). One end of the first circuit line (41) is connected to the first pin (21), and the other end of the first circuit line (41) is connected to one pole of the laser chip (3). One end of the second circuit line (42) is connected to the second pin (22), and the other end of the second circuit line (42) is connected to the other pole of the laser chip (3), so as to connect the two poles of the laser chip (3) with the first pin (21) and the second pin (22) through the FPC flexible strip (4). Among them, the FPC soft strip (4) is a poor conductor of heat. Using the FPC soft strip (4) effectively avoids heat exchange between the laser chip (3) and the external environment.

2. The DFB device with refrigeration of claim 1, wherein, Matching resistors are provided on the first circuit (41) and / or the second circuit (42) to improve signal integrity.

3. The DFB device with cooling according to claim 1, characterized in that, The DFB device with cooling also includes a backlight detection chip (5), a first light output port (31) is provided on the laser chip (3), and a third pin (23) is provided on the TO base (2). The backlight detection chip (5) is electrically connected to the third pin (23), the backlight detection chip (5) is disposed on the ceramic substrate (6), and the backlight detection chip (5) is coupled and aligned with the first light outlet (31).

4. The DFB device with cooling according to claim 3, characterized in that, A thermistor (7) is disposed on the ceramic substrate (6), and a fourth pin (24) is disposed on the TO base (2); the thermistor (7) is electrically connected to the fourth pin (24).

5. The DFB device with cooling according to claim 3, characterized in that, The DFB device with cooling also includes a reflector (8), and the laser chip (3) is provided with a second light output port (32). The reflector (8) is disposed on the ceramic substrate (6), and the reflector (8) is coupled and aligned with the second light outlet (32) of the laser chip (3); The reflector (8) has a light-incident surface (81), which is set at a first preset angle with the second light-out port (32). The light-incident surface (81) is used to refract light signals.

6. The DFB device with cooling according to claim 1, characterized in that, The DFB unit with cooling also includes a TO cap (9), an adapter (10), and a tube body (11). The TO cap (9) is disposed on the TO base (2), and an optical fiber is disposed inside the adapter (10); One end of the tube (11) is fitted onto the TO cap (9), and the other end of the tube (11) is connected to the adapter (10).

7. The DFB device with cooling according to claim 6, characterized in that, An adjustment ring (12) is provided between the adapter (10) and the tube (11). The adapter (10) is rotatably mounted on the adjustment ring (12) so as to couple the optical fiber in the adapter (10) with the optical signal generated by the laser chip (3).

8. A method for assembling a DFB device with cooling, characterized in that, The assembly method is applicable to the DFB device with cooling according to any one of claims 1-7, and the assembly method includes: The TEC (1) is mounted on the TO base (2), and the laser chip (3) is placed on the TEC (1); Connect one end of the first circuit line (41) printed on the FPC flexible tape (4) to the first pin (21) on the TO base (2), and connect the other end of the first circuit line (41) printed on the FPC flexible tape (4) to one pole of the laser chip (3); One end of the second circuit line (42) printed on the FPC flexible tape (4) is connected to the second pin (22) on the TO base (2), and the other end of the second circuit line (42) printed on the FPC flexible tape (4) is connected to the other pole of the laser chip (3) to realize the connection between TEC (1), TO base (2), laser chip (3) and FPC flexible tape (4).

9. The assembly method of the DFB device with cooling according to claim 8, characterized in that, It also includes the assembly of the adapter (10), adjustment ring (12), tube body (11), TO cap (9), backlight detection chip (5), ceramic substrate (6), reflector (8) and thermistor (7), the assembly method specifically includes: The ceramic substrate (6) is attached to the TEC (1), and the laser chip (3), backlight detection chip (5), reflector (8) and thermistor (7) are attached to the preset positions on the ceramic substrate (6), and the TEC (1) is attached to the TO base (2). The laser chip (3) is connected to the TO base (2) via FPC flexible tape (4), the backlight detection chip (5) is connected to the third pin (23) via gold wire, and the thermistor (7) is connected to the fourth pin (24). Install the TO cap (9) on the TO base (2) and attach one end of the tube body (11) to the TO cap (9); Install an adjustment ring (12) on the other end of the tube (11) and install the adapter (10) on the adjustment ring (12). Rotate the adapter (10) so that the optical fiber inside the adapter (10) is coupled and aligned with the optical signal generated by the laser chip (3).

10. The assembly method of the DFB device with cooling according to claim 8, characterized in that, Before connecting the laser chip (3), third pin (23), and fourth pin (24) using the FPC flexible strip (4), a matching resistor (43) is also provided within the FPC flexible strip (4), specifically including: Monitor the oscillation circuits at both ends of the laser chip (3), adjust the matching resistor (43) on the FPC soft strip (4) from 0Ω each time with a preset gradient step, and measure the integrity of the output signal of the FPC soft strip (4) under each matching resistor (43); Once the integrity of the monitored signal reaches the preset effect, the final target matching resistance (43) value on the FPC soft band (4) is obtained.

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